In the past, felting needles have been grouped in two general types. The first type is the regular felting needle with a round, pointed end and barbs spaced at various points along the lateral edge of the blade. Such a needle is designed to interlock fibers so as to produce a felted fabric. The second type of needle is the forked needle which has two spaced-apart points and a fiber receiving slot between them for pushing fibers toward a batt. The primary function of such a needle is to embellish the surface of felted fabrics.
Patents which illustrate needles in the first group are my own U.S. Pat. Nos. 3,307,238; 3,641,636; 3,815,186; 3,844,004; and 4,156,305; and patents which illustrate needles in the second group are my own U.S. Pat. Nos. 3,727,276 and 4,110,875. The older, long-established felting needle with barbs formed in longitudinal lateral edges of the needle body have long been known, and specific terminology has become identified with such needles, such as barb angle, throat depth, kickup and throat length. Such portions of a felting needle must be held to very close tolerances to make possible the production of the desired fabric. Barb angles, with their precise forward inclination, are very critical. It is essential on the regular felting needle that the barb angle be such that engaged fibers can shed off the barb tip and be felted into the fabric. The design of the forked needle with longitudinal sidewalls adjacent the fiber-receiving slot makes shedding impossible and confines the function of the needle to the production of fiber loops and tufts.